This invention relates to a device for applying a force to a chain, and, more particularly, to a manually operated tool for pulling a chain.
Winching equipment for applying a force to drag or lift an object is well known. In particular, with the increased popularity of off-road recreational vehicles, there is an increased demand for winching units that will allow the vehicle to be rescued in the event that it becomes stuck. In the past, this has often involved equipping the vehicle with a powered winch or similar equipment that can pull a trapped vehicle toward an anchored object by winding a cable or chain about a receiving drum. A power take-off or a separate motor is used to rotate the drum to receive the cable or chain. Winding of the cable or chain about the drum does not generally provide any mechanical advantage and a powerful and expensive winch motor is generally needed. This makes the winch unit expensive and bulky. The winch unit is generally installed on the exterior of the vehicle for ready access and is often exposed to the environment. Since the winch is not used on a regular basis, it tends not to be maintained as diligently as other components of the vehicle. Infrequent use in combination with exposure to the elements often results in the winch unit being prone to failure when needed.
Winches, whether operated manually or by a motor, are also useful for lifting loads vertically or for pulling an object remote from the winch. For example, a winch can be operated to drag a downed tree from a position blocking a road or from a tree felling site to a wood processing area.
My invention relates to a tool that is particularly useful as an inexpensive replacement for existing winch equipment. I have developed a compact, reliable manually operated tool that provides a significant mechanical advantage. As a winch replacement or xe2x80x9ccome-alongxe2x80x9d, the tool allows an operator to apply a considerable pulling force to xe2x80x9creel inxe2x80x9d a cable or chain.
The tool can also be operated to move along a fixed cable or chain. In this mode of operation, the tool can support a weight that is carried along the cable or chain.
Accordingly, the present invention provides a tool for applying a force to a chain, the tool comprising:
a lever;
an attachment member pivotally connected to the lever;
two opposed arms pivotally mounted to the lever on opposite sides of the attachment member, each arm having an end adapted to releasably engage and hold the chain; and
a linkage between the arms to guide movement of the arms upon reciprocal pivotal movement of the lever with respect to the attachment member, the arms being operable in a cycle in which one of the arms is maintained stationary to engage and hold the chain while the other arm is released from the chain and moved generally parallel to the chain past the stationary arm to engage and hold a new location on the chain whereupon each arm assumes the role of the other arm to complete the cycle.
The present inventions also provides a tool for applying a force to a chain, the tool comprising:
a handle;
an attachment member pivotally connected to the handle;
two opposed arms pivotally mounted to the handle on opposite sides of the attachment member, each arm having an end adapted to releasably engage and hold the chain; and
a link associated with each arm, each link being pivotally connected at one end to the arm and pivotally connected at the other end to the attachment member to control movement of each arm with respect to the chain on reciprocal pivotal movement of the handle with respect to the attachment member to cause the arms to move in hand-over-hand fashion along the chain such that one arm holds the chain while the other arm moves generally parallel to the chain past the one arm to engage and hold a new location whereupon the other arm holds the chain and the one arm moves in a repeating cycle.
In a further aspect, the present invention provides apparatus comprising:
an elongate member and a tool for travelling along the elongate member, said tool comprising:
a lever;
an attachment member pivotally connected to the lever;
two opposed arms pivotally mounted to the lever on opposite sides of the attachment member, each arm having an end adapted to releasably engage and hold the elongate member;
a linkage between the arms to guide movement of the arms upon reciprocal pivotal movement of the lever with respect to the attachment member, the arms being operable in a cycle in which one of the arms is maintained stationary to engage and hold the elongate member while the other arm is released from the elongate member and moved generally parallel to the elongate member past the stationary arm to engage and hold a new location on the elongate member whereupon each arm assumes the role of the other arm to repeat the cycle.